The primary objectives of this research are to prepare a wide variety of pentasubstituted and hexasubstituted phosphorus compounds. Methods for the production of P(V) compounds include a variety of cycloaddition and condensation reactions of P(III) and P(IV) compounds with a variety of reagents, biphilic insertion reaction of P(III) compounds into sigma bonds, and exchange reactions of P(V) compounds. The P(VI) compounds will be prepared by nucleophilic addition to a wide variety of P(V) compounds, and by exchange reactions. It is anticipated that this research will yield a large number of materials with novel structures. These substances will be submitted for biological testing. Other work will include studies of intramolecular ligand reorganization of the P(V) compounds, NMR investigations of their structures, and studies of their chemical properties and reactions.